1. Field
This application relates to systems that transfer or convert power or energy delivered by a prime mover into useful energy and more particularly to systems which receive power or energy in from a source that delivers power through a shaft that rotates at variable rates and generates an output at a desired rotation rate such as one that is essentially or substantially constant and even more particularly to systems that convert energy from a prime mover like a propeller driven by wind, a water turbine, or a wave turbine, into AC power.
2. The Relevant Technology
Wind turbines (e.g., GE Energy 1.5 mw series wind turbine found at http://www/gepower.com), water turbines (e.g., http://en.wikipedia.org) and wave turbines (e.g., Islay Wave Power Station reported by the BBC at http://news.bbc.co.uk/1/hi/sci/tech/103148.stm) have been developed for, among other things, generating electrical power. However, because the wind speed is variable, because wave characteristics such as height and frequency vary with many factors including wind speed and direction, and because the water flow rates from dams vary with season and weather, the electrical power produced by generators powered by such (hereinafter called “environmentally powered generators”) is typically produced at electrical frequencies which vary widely and somewhat randomly with related natural phenomenon. Because power distribution (into the power distribution grid) and power obtained by users receiving power from such a generator or the grid needs to be at or very close to a selected and stable frequency, like 60 Hertz (Hz) in the United States, the power from the environmentally powered generators must be converted to the desired or selected stable frequency by suitable frequency conversion devices (e.g., the 1.5 mw series GE wind turbines are reported to be connected to a pulse width modulated IGBT frequency converter). Devices for converting input power at variable frequency to output power at a stable frequency are believed to be inefficient. As a result, it is believed that much useful power or electrical energy generated by environmentally powered generators is lost or wasted. Inasmuch as the amount of electrical power supplied to the various power grids across the United States by environmentally powered turbines is increasing, it can be seen that much power is being wasted in connection with conversion to power grid frequencies.
Systems to extract more of the useful energy from the environmentally powered generators are not known. That is, systems to power the environmentally powered electrical generators at a constant rotation rate from the prime mover that has a variable rotation rate are not known. Indeed, systems for efficiently supplying rotational energy or torque at a constant shaft rotation rate using energy or torque delivered by a shaft powered by any prime mover that supplies power at a rotation rate that varies are not known.